Abstract

Nitrogen atoms in the cleaved (1 -1 0) surfaces of dilute GaAsN and
InGaAsN alloys have been studied using cross-sectional scanning
tunneling microscopy. The distribution of nitrogen atoms in
GaAs0.983N0.017 and
In0.04Ga0.96As0.99N0.01
alloys is found to be in agreement with random statistics, with the
exception of a small enhancement in the number of [001]-oriented
nearest neighbor pairs. The effects of annealing on
In0.04Ga0.96As0.99N0.01
alloys has been studied by scanning tunneling spectroscopy. Spectra
display a reduced band gap compared to GaAs but little difference is
seen between as-grown versus annealed InGaAsN samples. In addition,
voltage dependent imaging has been used to investigate second-plane
nitrogen atoms.